Semiconductor devices are used in a large number of electronic devices, such as computers, cell phones, and others. Semiconductor devices comprise integrated circuits that are formed on semiconductor wafers by depositing many types of thin films of material over the semiconductor wafers, and patterning the thin films of material to form the integrated circuits. Integrated circuits include field-effect transistors (FETs) such as metal oxide semiconductor (MOS) transistors.
One of the goals of the semiconductor industry is to continue shrinking the size and increasing the speed of individual FETs. To achieve these goals, planar fully depleted SOI devices, and non-planar devices such as fin FETs (FINFETs) or multiple gate transistors will be used in sub 32 nm transistor nodes. For example, FINFETs not only improve areal density but also improve gate control of the channel, which is a serious threat to scaling planar transistors.
However, besides high performance devices, which are typically low voltage circuits, other high voltage devices are essential for every technology. Example of high voltage devices include input/output devices. High voltage devices are traditionally produced using a thicker gate oxide, longer channel length, changing the doping etc. However, such options are not feasible in non-planar device technologies which require fixed design space to minimize process variations and reduce process complexities.
Accordingly, what is needed in the art are high voltage devices that are compatible with non traditional device architectures and design space while at the same time overcoming the deficiencies of the prior art.